The long-term objective of this proposal is to develop prostate-specific anticancer agents for treatment of prostate cancer. To achieve this objective it is proposed to use antiprostate antigen immunoglobulin G (antiPA IgG) antibodies as carrier for 131I or anticancer drugs. Therefore, our specific aims are (i) preparation of 131I-antiPA IgG antibody conjugate; (ii) Preparation of drug-antiPA IgG antibody conjugate; drugs employed are 5-fluorouracil deoxyriboside (FUdr), adriamycin and estracyt; (iii) Evaluation of antitumor activities of these conjugates against human prostate tumor in cell culture and in athymic mice. The antibodies will be isolated and purified from rabbit antiserum to prostate antigen by ammonium sulfate precipitation, DEAE cellulose chromatography, and affinity chromatography, employing purified prostate antigen as immunoadsorbent. In addition, monoclonal antiPA antibody will be used. 131I or anticancer drugs will be linked to these immuno-purified antibodies or monoclonal antibody with established procedures which have been used successfully in the principal investigator's laboratory in coupling 131I, FUdr and adriamycin to rabbit antiPA IgG. The activities of resulting conjugates will be evaluated in tissue culture system and in athymic mice bearing human prostate tumor.